#79: Strange Days on Saturn’s Moons

“Frozen” does not mean “static,” at least not among the icy moons orbiting Saturn. A remarkable 2010 image from NASA’s Cassini probe—now in its seventh year orbiting the ringed planet—shows just how dynamic these frigid worlds really are.

Thomas Romer and Gordan Ugarkovic, graphic designers who specialize in astronomical images, produced this portrait by merging two Cassini shots taken minutes apart as the probe whizzed past Enceladus on May 18. Titan, Saturn’s largest moon, dominates the view. Its thick, opaque orange atmosphere rains liquid methane, which flows into lakes on the surface. The foreground action here comes from another Saturnian moon, 310-mile-wide Enceladus, which emits huge jets of icy particles, here dramatically backlit by the sun. The material in these plumes may originate in an underground ocean before being forced to the –300 degree Fahrenheit surface and spewed out through cracks at the moon’s south pole. That spooky line cutting across the scene is an edge-on view of Saturn’s rings.